I INTRODUCTIONRecent work on floating exchange rates has emphasized the short-run volatility of exchange rates, especially in response t o unanticipated monetary disturbances. The principal statement of this view is found in the "exchange rate overshooting" hypothesis popularized by Dornbusch (1976 and 1979) and similar results are stressed in subsequent work such as Mathieson (1977) ; Bilson (1979) and Witte (1979). The opposite view, however, is expressed by Niehans (1977) who argues that the main drawback of Dornbusch (1976) (and of subsequent work within that framework) is the neglect of the interaction between trade flows and asset stocks. Thus, Niehans (op. cit.) finds that monetary expansion is inevitably associated not with "overshooting" but with "undershooting" of instantaneous exchange rates. Niehans's analysis, while interesting, is however marred by limitations of its own. For example, the real sector is completely excluded and all considerations of expectations and of the capital account (which appears to be an important, source of exchange rate volatility) are ignored. This paper may be viewed as an extension of the Dornbusch and Niehans lines of inquiry and is an attempt to integrate them. Specifically, it extends Niehans's analysis by incorporating interest-bearing assets and expectations as well as by providing a role for the trade and capital accounts. It also generalizes Dornbusch's work by allowing for non-instantaneous adjustment in money and security markets. The resulting framework involves considerable interplay between the real and asset sectors of the economy and an implication of the analysis is that unlike Dornbusch (1976), the short-run exchange rate is not determined excluGively in asset markets but instead by the full general equilibrium interaction of commodity and asset markets and only in special cases (of which Dornbusch's work is one example) does a valid dichotomy exist. 'Manuscript received 14.3.80; final version received 2.2.81. tThs is a revisedversion of an earlier paper written in February, 1980. entitled "On Exchange Rate Behaviour With Lagged Asset Adjustment". The author has benefited from reading an unpublished paper by Jacob Frenkel. 165